Transmission for concrete mixers

ABSTRACT

Between the motor and the bowl is a transmission and speed control shifter. The shifter is a two position shifter in which the bowl can be driven at either high or low speed depending upon charging, discharging and transit conditions. The transmission consists of three stages each comprised of a planetary gear system. The shifter in one position utilizes only a portion of the first stage and then transmits further power through the entirety of the second and third stages. In a second position the shifter utilizes the entirety of the planetary gear systems of the first, second and third stages to achieve lower speed mix rate of the bowl. The two advantages sought and obtained are that presently installed and used transmission systems can be modified to secure two speed control and the additional transmission elements are all of standard size and construction.

United States Patent 11 1 Sims [ TRANSMISSION FOR CONCRETE MIXERS RoyalW. Sims, 6500 Holladay Blvd., Salt Lake City, Utah 84121 22 Filed: June7,1973

21 Appl. No.: 367,707

[76] Inventor:

[52] US. Cl. 74/769; 74/330; 74/768; 259/177 [51] Int. Cl. Fl6h 57/10;F16h 3/08; B28c 5/18 [58] Field of Search 74/769, 768, 330; 259/177 R,177 A [56] References Cited UNITED STATES PATENTS 712,058 10/1902 Gloaget al. 74/768 2,052,815 9/1936 Wilsing 74/769 2,445,573 7/1948 Godbc,Jr. .1 74/764 2,620,679 12/1952 Issigonis et al. 1. 74/330 X 3,290,96212/1966 McCam et a1. 74/768 X 3,371,543 3/1968 Jackson et a1. 259/177 RX FOREIGN PATENTS OR APPLICATIONS 416,331 9/1934 United Kingdom 74/768Primary ExaminerSamuel Scott Assistant Examiner-P. S. Lall [5 7 ABSTRACTBetween the motor and the bowl is a transmission and speed controlshifter. The shifter is a two position shifter in which the bowl can bedriven at either high or low speed depending upon charging, dischargingand transit conditions. The transmission consists of three stages eachcomprised of a planetary gear system.

The shifter in one position utilizes only a portion of the first stageand then transmits further power through the entirety of the second andthird stages. In a second position the shifter utilizes the entirety ofthe planetary gear systems of the first, second and third stages toachieve lower speed mix rate of the bowl. The two advantages sought andobtained are that presently installed and used transmission systems canbe modified to secure two speed control and the additional transmissionelements are all of standard size and construction.

9 Claims, 4 Drawing Figures PATENTEU mczsms 3,901,104

sum 1 er 3 PATENTED AUEZBIQYS SEIEZT 2 [IF 3 3o [/10 '2 A I -1 B 24FIGURE 2 30 FIGURE 3 PATENTEU mczsms SHEET 3 BF 3 uw hm hmtfm FIGURE 4TRANSMISSION FOR CONCRETE MIXERS BACKGROUND OF THE INVENTION It isadvisable to provide the user of a self-propelled transit concrete mixerwith a two speed transmission system since the bowl should be rotatedrapidly during the period in which the bowl is charged with concretemixture ingredients and should again be rotated rapidly during the timeof discharge.

During transit, however, it is only necessary that the bowl turn overslowly, just sufficiently to prevent setting up of the interior contentsof the bowl. In fact, the problem of the art is how to achieve asufficiently low rate of rotation of the bowl so that it is notovermixed. If, during transit, the bowl should rotate an excessiveamount the bowl wears excessively and the overmixed aggregate (ormixture) is less fit for its intended purpose and is thereforerejectable. What is needed, is a new and improved transmission,preferably one which can be made of standard parts and utilizing readilyavailable planetary gear components and which can be produced from anexisting transmission which does not have the advantages of the presentinvention. In other words, existing self-propelled concrete mixtureswhich do not have the features of the present invention can be readilymodified by incorporating conventional or readily available componentswhich will basically alter the transmission to incorporate theadvantages of a two speed transmission drive between the motor and thebowl.

OBJECTS OF THE INVENTION It is a principal object of the presentinvention to provide a transmission consisting of first, second andthird stages each comprising planetary gear members which in combinationare capable of driving a bowl at two distinct speeds; a fast speedduring loading and unloading, and a slow speed during transit.

A second object of the present invention is to provide a new andimproved operator mechanism which is manually controlled and includestwo drive members one of which utilizes only a portion of the firststage of a three stage planetary gear system and thereby achieves a fastrate of bowl rotation and a second operator mechanism which utilizes theentirety of the first, second and third planetary gear systems toachieve a slower rotation of the bowl during transit.

A further object of the present invention is to utilize a transmissionsystem consisting of uniform components making up a planetary gearsystem wherein a first stage planetary gear system is interfaced with asecond planetary gear system which in turn is interfaced with aplanetary gear system of a third stage. These three stages areinterconnected in either one of two manners, through the first stage, toeffect high and low speeds of rotation of a bowl.

Other objects and features of the present invention will become apparentfrom a consideration of the following description which proceeds withreference to the accompanying drawings.

DRAWINGS FIG. 1 is a section view of a transmission system and shiftermechanism and illustrating the direction of movements of the shiftermechanism to achieve the selected rate of rotation of the bowl;

FIGS. 2 and 3 are detailed views illustrating the two positions for theshifter mechanism the high speed shifter position being illustrated inFIG. 2 and the low speed being illustrated in FIG. 3; and,

FIG. 4 is an exploded view illustrating the shifter mechanism and thefirst, second and third stages of planetary gears which are interfacedto produce the desired speed of bowl rotation.

SPECIFIC WORKING EXAMPLE OF THE INVENTION Referring to FIG. 1, a shiftermechanism designated generally by reference numeral 10 is effective forcoupling a motor or engine 12 and a sprocket 14 having a chainconnection (not shown) with a mixer bowl (also not shown).

The shifter mechanism 10 determines the path of force as it movesthrough a first stage 16, a second stage 18 and a third stage 20, eachstage consisting of a planetary gear arrangement prior to ultimatecoupling of the engine 12 with the sprocket 14 which is mounted on driveshaft 22.

The shifter mechanism consists of a shifter plate 24 and shifter plate26 the positions of which determine the rate of speed at which the bowlwill rotate. During charging and discharging of the bowl, the bowl speedshould be at a high rate, and during transit the bowl should rotate at arelatively slow rate so as not to exceed a predetermined total number ofrevolutions from the time of initial charging of the bowl with theconcrete mixture ingredients to the time of discharging such mixtureingredients at the construction site. The shifter plates 24, 26 haveassociated operator rods 30, 32 that determine the coupling of gearsthrough the first stage 16 (FIG. 4) previously pointed out to be aplanetary gear system. When it is desired to rotate the bowl at a highspeed, the rod 30 associated with plate 24 is moved toward the right(FIG. 2) and the rod 32, together with plate 26 is moved to the left(FIG. 2) thus disengaging the splined end 40 of rod 42 from sun gear 44and engaging the gear member 46 with a sleeve 48 having internal gearteeth 50. The sleeve 48 has a flange 54 which is connected with ahousing 56 and the housing is coupled through rods 58 to a backingmember 60 having internal gear teeth 62 which mesh with the gear teeth64 of a transfer rod 66.

The transfer gear rod 66 has gear teeth 68 which operates first the sungear 70 of the second stage planetary gear system 18. The second stageplanetary gear system 18 and the third stage planetary gear system 20(FIG. 4) are operatively connected together so that they in turn willoperate the shaft 22 and rotate the sprocket wheel 14 at a relativelyhigh rate of speed as for example 18-20 revolutions per minute. But oncethe bowl is fully loaded it is then desired to reduce the rate of mixingof the ingredients within the bowl and at that point the shifter isagain operated and at this time the rod 30 is moved to the left A(FIG. 1) disengaging the gear 46 from the associated gear teeth 50 ofsleeve 48 and the rod 32 connected with plate 26 is moved toward theright, in the direction indicated by the letter B in FIG. 1, engagingthe gear teeth 40 of rod 42 with sun gear 44 so that the first stageplanetary gear system 16 is connected with the second stage 18 throughthe backing member 60 thence through transfer gear rod 66 and then tothe second and third stage gear mechanisms 18 and 20.

Referring to FIG. 4, the first stage 16 is housed in part by an endcover 80 which is secured to a casing 82 (FIG. 1) which in turn isfastened to a chain housing 84.

Each of the first, second and third stages is essentially identical inthe respective gear arrangement other than the arrangement that thefirst stage 16 has its initial motor input through gear 40 or gear 46.Since the various planetary gear arrangements are identical except asnoted; only one will be described it being understood that the gearparts are for the most part interchangeable thus making for economy ofmanufacture and service. The planetary reducer is standard and isobtained from either Blaw Konx or Funk.

Referring to the planetary gear arrangement in the first stage 16 (FIG.4) there is a ring gear 78 with an O- ring seals 92 and 94 one on eachside thereof. The ring gear has meshed therewith three planetary gears76 which are supported by associated pivot pins 98, plates 100 andbearings 102.

As shown in the first stage, each planetary gear is supported onplanetary gear plates 104 and 106 and the planetary gears are operatedby sun gear 44 which is directly drivable by the splined end 40 of shaft42.

Force is transmitted from one stage to the next by means of connectingshafts 66 which couple the first stage 16 to the second stage 18 andthere is a corresponding second shaft 66 connecting the second stage 18to the third stage 20 (FIG. 1).

All that is required to change bowl speed is to move the rods 30, 32 insome suitable mechanical manner thus effecting either a connection fromthe motor 12 through the motor shaft 110 through gear 40 (note operativeposition in FIG. 1) and establishing a slow bowl rotational speedwherein the shifter elements are disposed as in FIG. 3; or, the shifterelements are moved to the positions shown in FIG. 2 wherein 40 isdisengaged from the sun gear 44 of the first stage 16 and instead gear46 is connected with sleeve 48 which in turn is connected to the casin g56 to effect a bypass of a portion of the gear arrangement in the firststage 16 and produces through the second 18 and third 20 stages a fasterrate of speed of the bowl.

The output shaft 22 is mounted on roller bearings 120 and 122 spaced oneat each end of the shaft 22 and the sprocket 14 has a chain connectionwith the bowl. The sprocket wheel 14 is positioned by a spring 128 andit can float on the shaft 22 through a splined connection 129 so as toremain mounted in a proper relative position in relation to the bowl inspite of its inevitable shifting movements by means of a spring 128.Details of the mounting of the sprocket wheel 14 may be obtained byreference to copending application Ser. No. 348,209 filed Apr. 5, 1973entitled CHAIN TEN- SIONING DEVICE.

OPERATION In operation, it is a relatively simple matter to change thebowl rotational speed by means of the actuating mechanism whichmechanically operates one or the other of the plates 24 or 26,positioning them either in the position shown in FIG. 2 or FIG. 3.

When it is desired to rotate the bowl at a fast rate of speed which isthe case during charging and discharging, the plates 24 and 26 arepositioned as shown in FIG. 2 in which the gear member 46 is engagedwith the coacting gear teeth 50 of sleeve 48 and the motor 12 is thencoupled through motor shaft 1 10 and gear member 46 to sleeve 48, flange54, housing 56, rod 58, backing member 60 and thus through the firststage 16 to the second stage 18 through a transfer rod 66 which effectsthe transfer through gear teeth 64 and gear teeth 68. Force then movesthrough the second and third stages 18 and 20 in a conventionalplanetary gear fashion to drive shaft 22 having splined connection 129with sprocket wheel 14. The sprocket 14 has a chain drive connection(not shown) with the bowl (not shown). When the shifter mechanism ispositioned as shown in FIG. 2 the bowl rotates at a high rate ofrotation.

During transit, when the speed of rotation should be relatively slow,just sufficient to prevent the aggregate from setting up, the bowlrotates, just turning over, in order that the aggregate is not overmixedand to prevent excessive wear of the interior components of the bowl. Inthis case, the shifter mechanism is changed from the position shown inFIG. 2 to that of FIG. 3 in which the plate 24 is moved to the leftdisengaging gear member 46 from sleeve 48 and the plate 26 is moved tothe right engaging gear end 40 with sun gear 44.

In this case, the motor 12 is coupled through the output shaft throughgear end 40 ,with sun gear 44, planetary gears 76 and backing member 60to transfer rod 66 thus transferring motive force from the first stage16 to the second stage 18. Motive force is transferred from second stage18 to third stage 20 as previously described and thus the entirety ofthe planetary gear systems of the first, second and third stages isutilized between the motor 12 and the output shaft 22. The output shaftand splined sprocket 14 are thus rotated at a relatively slow speed inthe order of only one or two revolutions per minute thus preventing theaggregate from overmixing during transit.

One of the major advantages of the present invention is that it is sosimple to adapt conventional transmissions by simply adding the shiftermechanism, and adding the first stage support plate and the additionaltransfer gear rod. These are relatively easy operations to perform andthe entirety of the gear system is made up of uniform sized components.

The gear system is lubricated by incorporating the entirety of thefirst, second and third stages and shifter mechanism within a sealedsystem wherein all of the gears and shifter mechanism are sealed and arelubricated.

What the new development consists then is an increase in gear reductionfrom a typical present reduction ratio of 15:1 to 45:1 so that the bowlcan be rotated at whatever speed is desired as for example 23 to 24 rpmin the high range to enable faster charge time and discharge timewhereby less material is spilled and the bowl is cleaner; and, at thelower range of bowl speed, the aggregate is protected from overmixingand excessive bowl wear. Because of the improved bowl gear reduction,ample power is available at the lower range of bowl rotation so that thebowl can always or nearly always be rotated and after it has beenstopped for excessive periods thus preventing set up of the aggregate inthe bowl resulting in catastrophic loss of the bowl.

Also, the low range bowl drive speed results in a power saving in thehydraulic unit (since the hydraulic motor is driven from the primemover) and the additional power available contributes to increased powerfor the vehicle drive train. Thus, the vehicle can move over steepergrades and at faster speeds than heretofore.

The operating mechanisms for shifting the plates 24, 26 can be eithermanual, hydraulic or pneumatic according to desired preference.

Although the present invention has been illustrated and described inconnection with a few selected example embodiments, it will beunderstood that these are illustrative of the invention and are by meansrestrictive thereof. It is reasonably to be expected that those skilledin this art can make numerous revisions and adaptations of the inventionand it is intended that such revisions and adaptations will be includedwithin the scope of the following claims as equivalents of theinvention.

What I claim is:

1. An improved transmission for concrete mixers comprising a shiftermechanism having two independently movable and relatively laterallydisplaceable first and second drive members, said first drive memberbeing selectively movably into engagement with a sun gear of the firstof three intermittently engageable planetary gear assemblies, saidsecond and third planetary gear assemblies being connected seriallytogether and to a preselected portion of said first planetary gearsystem to effect a drivable connection between a prime mover and amixing bowl, said second independently movable drive member beingselectively engageable with a second portion of said first planetarygear assembly when said first drive member is disengaged to provide asecond drive connection effecting a different speed between said primemover and bowl and consisting of a gear member which forms a directdrive with a different portion of said first planetary gear assemblythan said first drive and bypassing the sun and planetary gear portionof said first planetary assembly but utilizing the interfaced second andthird planetary gear assemblies.

2. The improved transmission in accordance with claim 1 wherein theplanetary gear arrangements are disposed in series and are selectivelycoupled to effect, in accordance with the gear train, a selected bowlspeed control.

3. The improved transmission in accordance with claim 1 includingoperating means which are splined together to provide co-rotating firstand second gear means selectively engageable with a predeterminedportion of the adjacent planetary gear of the first of three in-seriesplanetary gear systems.

4. The improved transmission in accordance with claim 1 wherein thefirst, second and third stage planetary gears are connected in seriesand means for acting only through a portion of the first stage, andmeans for acting through the entirety of said first stage whereby theoutput of said first stage to the combination of the successivelyconnected second and third stages determine the bowl speed.

5. The improved transmission in accordance with claim 1 wherein each ofthe sun, planetary and ring gears of the three stages is of standardsize and construction.

6. The improved transmission in accordance with claim 1 includingmechanically operable means for laterally shifting on splineconnections, a first and second gear operator which determines theoperative portion of the first planetary gear stage operated thereby.

7. A process for transmitting rotational energy to a mixing bow] at oneof two preselected speeds comprising the steps of selectively engagingindependently movable and relatively displaceable first and second drivegear members of a first stage planetary gear system, coupling said firststage with a combination of inseries second and third stage planetarygears and connecting the output of said third stage to a bowl foreffectively driving said bowl at a predetermined speed.

8. The process in accordance with claim 7 including the step ofmechanically shifting relatively to each other one of two gear operatorsto effectively determine the rate of bowl speed.

9. The process in accordance with claim 7 wherein said first stageplanetary gear includes sun, planetary and ring gear portions which arepredeterminately operated and transmitting force from said first stageto successive second stage and third stage planetary gear systems,wherein that portion of said first stage is operated to effectivelydetermine bowl speedv

1. An improved transmission for concrete mixers comprising a shiftermechanism having two independently movable and relatively laterallydisplaceable first and second drive members, said first drive memberbeing selectively movably into engagement with a sun gear of the firstof three intermittently engageable planetary gear assemblies, saidsecond And third planetary gear assemblies being connected seriallytogether and to a preselected portion of said first planetary gearsystem to effect a drivable connection between a prime mover and amixing bowl, said second independently movable drive member beingselectively engageable with a second portion of said first planetarygear assembly when said first drive member is disengaged to provide asecond drive connection effecting a different speed between said primemover and bowl and consisting of a gear member which forms a directdrive with a different portion of said first planetary gear assemblythan said first drive and bypassing the sun and planetary gear portionof said first planetary assembly but utilizing the interfaced second andthird planetary gear assemblies.
 2. The improved transmission inaccordance with claim 1 wherein the planetary gear arrangements aredisposed in series and are selectively coupled to effect, in accordancewith the gear train, a selected bowl speed control.
 3. The improvedtransmission in accordance with claim 1 including operating means whichare splined together to provide co-rotating first and second gear meansselectively engageable with a predetermined portion of the adjacentplanetary gear of the first of three in-series planetary gear systems.4. The improved transmission in accordance with claim 1 wherein thefirst, second and third stage planetary gears are connected in seriesand means for acting only through a portion of the first stage, andmeans for acting through the entirety of said first stage whereby theoutput of said first stage to the combination of the successivelyconnected second and third stages determine the bowl speed.
 5. Theimproved transmission in accordance with claim 1 wherein each of thesun, planetary and ring gears of the three stages is of standard sizeand construction.
 6. The improved transmission in accordance with claim1 including mechanically operable means for laterally shifting on splineconnections, a first and second gear operator which determines theoperative portion of the first planetary gear stage operated thereby. 7.A process for transmitting rotational energy to a mixing bowl at one oftwo preselected speeds comprising the steps of selectively engagingindependently movable and relatively displaceable first and second drivegear members of a first stage planetary gear system, coupling said firststage with a combination of in-series second and third stage planetarygears and connecting the output of said third stage to a bowl foreffectively driving said bowl at a predetermined speed.
 8. The processin accordance with claim 7 including the step of mechanically shiftingrelatively to each other one of two gear operators to effectivelydetermine the rate of bowl speed.
 9. The process in accordance withclaim 7 wherein said first stage planetary gear includes sun, planetaryand ring gear portions which are predeterminately operated andtransmitting force from said first stage to successive second stage andthird stage planetary gear systems, wherein that portion of said firststage is operated to effectively determine bowl speed.